*Challenging* problem involving physics thermodynamics.

[Riddleman]

hi guys I've been having trouble with this one question can anybody help thanks.

11. Consider a hypothetical device that takes 10,000J of heat, hot reservoir and 5000J of heat from a cold reservoir in produces 15,000J of work. (A) Does this device violate the first law of thermodynamics? Explain. (B) Does this device violate the second law of thermodynamics? Explain.

 

[Riddleman]

bump

 

[nwfsnake]

Better find the nearest Holiday Inn Express!

Real World: Yes and Yes. Basically, it would take energy to do the work, so you could never get 15K out with 15K in.

Make Believe School Class answer: Who knows? Teachers are a pain and you never know how they want these kind of questions answered!

 

[fatalbert]

the first law is not broken, as energy is neither being created or destroyed.

Generally you deposit heat into a cold reservoir, because taking energy from it, decreases its entropy, without causing a more balanced etropy state like taking from the hot reservoir, so I think it violates the second law, but I'm not sure.


(note- I'm assuming ideal conditions for the first law).

 

[Riddleman]

thanks guy, amen to that last part.

 

[Howard]

I don't even understand the first sentence of the problem.